The present invention relates to an electro-optical system test tool and more particularly to a multifunction electro-optical system test tool capable of providing high resolution output information for high power and high pulse repetition frequency (PRF) laser optic devices.
A conventional electro-optical test tool is described, for example, in U.S. Pat. No. 4,693,600, which is hereby incorporated by reference. The optical beam analyzer described therein, includes an optical system for collecting a light beam to be analyzed and an array of light sensitive elements positioned at the focal plane of the optical system for receiving the incident light beam. The array is scanned so as to sequentially sample the incident light beam and the sampled information is then digitally processed to generate signals indicative of the characteristics of the incident light beam.
FIG. 1 shows a schematic diagram of such a conventional electro-optical test tool. The incident laser beam from the laser under test 1 is collected by a collecting optics arrangement 3 and made incident upon a focal plane at which is disposed a sensor array 4. The sensor array 4 may comprise a linear array of 1024 photodiodes. The incident laser beam is also partially reflected by reflector 2 to a detector 5 which outputs an initiate data scan signal (sync signal) to a scan-timing circuit 7. In response, the scan-timing circuit 7 supplies control signals to a video data processor 8 and an A/D converter 9. In response to the control signal, the video data processor 8 sequentially selects sensors of the sensor array 4 and couples the output signal of each selected sensor to the A/D converter 9.
In response to the control signal from the scan-timing circuit 7 and the output signal from the video data processor 8, the A/D converter 9 generates a digital number representative of the output signal of the selected sensor and outputs the digital number, along with an interrupt signal, to a digital processor 10. When the interrupt signal has been generated, the digital processor 10 outputs a scan control signal to scan control circuit 11. In response, the scan control circuit 11 generates output signals which are coupled to a positioning system 12 to sequentially move, in predetermined increments, the linear sensor array in the focal plane of the collecting optics 3 such that a selected area of the focal plane is scanned. In this manner, data in the form of digital numbers is generated and stored in a memory (not shown) which may be part of the processor 10, and is displayed on display device 13 for providing an energy profile of a scanned portion of the laser beam entering the collecting optics 3.
While this conventional optical beam analyzer provides an effective testing tool, it suffers from a number of performance limiting disadvantages. In particular, this conventional analyzer cannot effectively test a pulsed optical source having a pulse repetition frequency (PRF) greater than 100 hz. Furthermore, the processing circuitry is incapable of processing laser radiation pattern details corresponding to low level video information which limits the dynamic range of the testing device.